Drop-out fire vent

ABSTRACT

A fire venting skylight of the drop-out variety consisting of nested double domes. The outer dome which may be thicker than the inner dome is spaced from the inner dome except at its periphery. The periphery of the outer dome is clamped against the upper surface of the inner dome at a marginal distance from the edge of the inner dome. The outer dome has a diameter which is smaller than the diameter of the skylight well. The inner dome has a diameter which is larger than the inner diameter of the skylight well with the outer periphery of the inner dome resting on the curbing of the skylight.

ilmted States Patent 1191 1111 3,924,372 Anghinetti et al. Dec. 9, 1975 DROP-OUT FIRE VENT 2,842,073 7/1958 Huston et al. 52/200 3,005,291 10/1961 Huber 52/200 X [75] Inventors Joseph Anghmett" 3,127,699 4/1964 Wasserman..... 52/200 X Kennebuhkport; Paul Couture, 3,417,527 12/1968 Kiekhaefer 52/200 5 fi yb il llll J 3,731,442 5/1973 Kiyoshi 52/232 rt, f M

p a 0 am FOREIGN PATENTS OR APPLICATIONS [73] Assgneei pmducts Sanford 555 188 3/1957 Belgium 0 52/200 i Maine [22] Filed: Mar. 18, 1974 Primary ExaminerFrank L. Abbott Assistant ExaminerLeslie A. Brown [21] Appl' 452066 Attorney, Agent, or FirmWolf, Greenfield & Sacks Related US. Application Data [63] Continuation of set. N0. 291,978, Sept. 25, 1972, ABSTRACT abandoned A fire venting Skylight of the drop-out variety consisting of nested double domes. The outer dome which [52] US. Cl; 52/232; 52/200 y b thicker than the inner dome is Spaced from the [51] Illlt. Cl. E04B 7/18 inner dome except at its periphery The periphery of [58] Fleld of Search 52/1 2 98/42 the outer dome is clamped against the upper surface 98/86 49/1 8 of the inner dome at a marginal distance from the edge of the inner dome. The outer dome has a diame- [561 References Clted tel which is smaller than the diameter of the skylight UN TED TA S E S well. The inner dome has a diameter which is larger 540,821 6/1895 Smith 52/200 x n h n r iam r of the skylight well with the 1,379,359 /1921 Partzschefeld 52/200 X outer periphery of the inner dome resting on the curb- 2,182,852 12/1939 Mulford 52/200 X ing Of the skylight. 2,790,400 4/1957 Wasserman... 52/200 X 2,803,318 8/1957 Nickerson 49/7 15 Clalms, 4 Drawing Figures U.S. Patant Dec. 9 1975 Sheet 1 0f 2 3,924,372

U.S. Patent Dec91975 Sheet 2 of2 3,924,372

1 w w w DROP-OUT FIRE VENT This application is a continuation of application Ser. No. 291,978, filed Sept. 25, 1972, now abandoned.

SUBJECT MATTER OF THE INVENTION The present invention relates to a drop-out skylight construction and in particular to a drop-out skylight construction employing a plurality of domes and adapted for use with domes made of acrylic plastic.

BACKGROUND OF THE INVENTION Fire venting skylights generally fall into two classifications. One type of fire venting skylight is the type in which the cover or dome mechanically springs open on the occasion of a fire. In the second type the dome or covering drops downwardly on the occasion of a fire. The latter type of skylights have certain advantages over those which mechanically open. For one thing drop-out skylights generally do not have moving parts and do not require any maintenance. In addition, they are not usually affected by snow loads or wind. While drop-out units have these and other advantages over the mechanically operated types that pivot outwardly, the drop-out units which have been designed to date have some serious limitations which have materially affected their acceptability especially by various underwriters. The effectiveness of a fire venting skylight of the drop-out variety has been generally tested by determining how long it will take the skylight dome or cover to drop out upon the application of certain standards of heat. In one accepted test, devised by the Factory Mutual Research Corporation, the drop-out skylight is deemed to be acceptable if the cover unit will drop out within minutes when the temperature 1 inch below the cover is heated from room temperature to 500 F. in that 5 minute period while the top of that cover is subjected to a shower of cold water at a temperature on the order of 30 to 40 F. Commercial attempts to meet these requirements have necessitated the use of skylight domes made of polyvinylchloride (PVC). PVC has generally been used because it softens at 210 F. while the domes made of acylics, which are more desirable, soften at about 320 F. In units originally devised acrylic domes would not soften sufficiently within a 5 minute period to drop out. Accordingly, currently offered units use PVC domes. PVC domes, however, deteriorate by turning black and deforming due to weathering over a time period. It is also believed that they may become brittle after a period of time and accordingly may not work as effectively as originally intended.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a skylight fire venting dome construction in which domes of acrylic material may be used rather than PVC or other types of material. It is also an object of the present invention to provide an improved fire venting dropout skylight unit utilizing an acrylic dome which is capable of dropping out of the skylight frame within 5 minutes after the start of the application of heat which attains a temperature of 500 F. within one inch of the bottom of the dome while water having a temperature on order of 30 to 40 F. is showered on the top of the dome.

It is also an object of the present invention to provide an improved fire venting skylight dome which is easy to maintain, which does not require any moving parts, is

5 The outer dome preferably has a thickness greater than the inner dome is spaced from the inner dome except at its outer periphery which outer periphery is secured to the outer surface of the inner dome at a marginly spaced distance from the outer edge of the inner dome. The outer edge of the inner dome is supported on the skylight curbing with the outer dome periphery being secured against the outer surface of the inner dome. The present invention also provides an arrangement in which the skylight drop-out system may be used on a multiple dome configuration supported on a common frame in which the multiple sets of domes will drop out on the occurrence of excessive heat in much the same fashion as the single set of domed configurations.

DESCRIPTION OF THE DRAWINGS These and other objects and advantages of the present invention will be more clearly understood when considered in conjunction with the accompanying drawings in which:

FIG. 1 is a top plan view of the skylight embodying the present invention;

FIG. 2 is a fragementary cross-sectional elevation taken along the line 2-2 of FIG. 1;

FIG. 3 is a top plan view of a multiple dome configuration; and

FIG. 4 is a cross-sectional view taken along the line 4-4 of FIG. 3.

DETAILED DESCRIPTION Referring to the embodiment illustrated in FIGS. 1 and 2 there is shown a conventional body assembly 1 which preferably consists of a rectangular inner wall 2 and, where necessary, a parallel outer wall 3. The space between these walls 2 and 3 is closed by the bottom member 4. Wall 3 extends outwardly to form a securing and/or retaining flange 5 in a conventional fashion. A fiberglas insulation 6 is positioned within the space between the walls 2 and 3 and the top of this body assembly is covered by a curbing generally indicated at 7. In some cases the insulation is not used and only one upstanding wall is required. The curbing 7 which may be conventionally extruded includes an upwardly extending flange 8 on the inner side of the body assembly, outer flange l0 and horizontally extending flange 9 spanning and intermediate the inner flange 8 and outer flange 10. The flange 10 is provided with corner weep holes 11 just above the upper surface of flange 9. The lower edge of flange 10 extends downwardly in facing relation with outer wall 3. The upper end of flange 10 can be provided with a screw receiving shoulder 12 and an inwardly extending flange 13. The curbing 7 is formed of four segments mitered at the corners and secured suitably to the top of the body assembly to form a four-sided frameat the top of this assembly. The flanges 8, 9 and 10 form a condensation gutter for collecting condensate that may collect on the inside surface of the inner dome hereafter described.

A pair of domes 14 and 15 are supported above the curbing 7. Dome 14 which typically may have a thickness of 0.090 inch and is preferably formed of a conventional acrylic material, normally used for skylight domes, has a periphery which extends into a horizontally extending flange 16 integral with thecurved inner portion of the dome. The horizontal flange has an outer edge which defines the outer edge of the dome. This flange 16 rests on and is secured to flange 13 by means hereafter described. Preferably the width of flange 16 is essentially co-extensive with the width of the flange l3. Flanges 13 and 16 terminate outwardly of flange 8 so that condensation forming on the under surface dome 14 will run down the inner surface of the dome and drip into the condensation gutter formed by flanges 8, 9 and 10 and thence outwardly through the weep hole 11.

Positioned above the inner dome 14 is the outer dome 15 which may be thicker than the inner dome 14 and may, for example, have a thickness on the order of 0.125 inch. However, because the outer dome is generally cooler than the inner dome the outer dome does not have to be thicker than the inner dome. The inner and outer domes are spaced apart from each other thereby defining an air space 18. The domes, however, engage one another at the periphery of the outer dome 15 which terminates at its periphery in a horizontal outwardly extending flange 19 which is contiguous with the curved portion of the dome 15. The domes 14 and 15 preferably contact one another at essentially a point contact 20 defined by the intersection of the curved outer surface of dome 14 and the inner edge of flange 19. The outer dome 15 has an outer maximum diameter which is less than the outer maximum diameter of dome l4 and the line of engagement, shown at point 20 in FIG. 2, between the two domes is spaced inwardly from the outer periphery of dome 14. The outer dome 15 is secured at its periphery against dome 14 by the the retainer 22. The retainer 22 comprises an angle member including horizontal flange 23 and vertical flange 24. Vertical flange 24 is provided with a series of holes aligned with shoulder 12. A series of screws 25 extend through the flange 24 and are secured in shoulder 12 thereby securing the retainer 22 to the curbing 7. The horizontal flange 23 has two depending tabs 27 and 28 spaced parallel to one another with flange 27 extending downwardly into pressing engagement with a gasket 29 in turn resting on and extending co-extensively with flange 19. Flange 28 is spaced from the outer edge of flange 19 and is disposed close to the outer edge of flange 19 so as to limit the downward movement of dome 15. Excessive movement of dome 15 will cause the edge of flange 19 to interengage and be retained by flange 28. A block 30 integral with the undersurface of flange 19 is provided with a hole through which a braided steel cable 31 extends. The braided steel cable is looped and secured by clamp 32 to this block 30 at one end and at the other end is secured by a clamp 33 and looped about one of the screws 25.

In the operation of this unit on the occurrence of a fire heat rises and starts to soften the inner dome 14. The dome will ordinarily soften at its upper center portion first. Because of the air space 18 between the domes 14 and 15 the softening takes place rapidly and well within the 5 minute time limit referred to above. The outer dome acts as a heat retaining member insulating the inner dome from the effects of outside weather conditions thus permitting rapid softening. As the inner dome softens and begins to sag it will start to move downwardly and ultimately fall through the well 37. The dome softens sufficiently so that the outer periphery and flange of the inner dome will pull over the flange 8 and will not be caught on it. For this reason the distance between the inner edge of flanges 13 and 16,

and the inner flange 8 should be minimized while still permitting sufficient space for the collection of condensation. As the inner dome drops the outer dome which may be heavier and is cooler normally retains its shape and is not deformed. Because the outer diameter of outer dome 15 is smaller than the dimesion of the inner body wall 2, the dome 15 drops down through the well. To prevent the dome 15 from inadvertently flying or falling downwardly to floor level to possibly injure a fireman or other person below, the cable 31 holds the dome 15 inside the well.

Referring now to the embodiment illustrated in FIGS. 3 and 4 similarly numbered elements are of similar construction to the arrangement described in connection with FIGS. 1 and 2. In large skylight openings, however, it is not possible to make a skylight sufflcient to be self-supporting with a single span of plastic material unless the material is very thick. The thickness that would be required, however, for a dome 4 X 8 feet would be so substantial as to preclude efficient and desired softening of the dome within the time parameters referred to above. Accordingly, a fire venting skylight for relatively large skylight opening employs multiple sets of domes. In this arrangement there is generally shown one set of domes 40 and an adjacent set 41. These sets of domes 40 and 41 are secured by means described in connection with FIG. 1 along three sides. They are secured by somewhat different means, however, along their abutting or adjacent sides 43. In this arrangement a retainer 44 having a horizontal upper flange 45 is secured to a vertical flange 46 in turn secured at its lower end to a horizontal lower flange 47 that terminates at opposite ends in upwardly extending flanges 48 and 49 that form respectively gutters 50 and 51. The flange 45 may be secured symmetrically to flange 46 by a series of screws 52. Flange 45 on each end is provided with inner downwardly extending lips 53 and outer downwardly extending lips 54. Lips 54 engage gaskets 55 that are coextensive with the flanges 19 of the outer dome and secure this flange against the inner dome 14. The lip 53 has a similar function to the flange 28 shown in FIG. 2.

The retainer and associated condensation gutters illustrated in FIG. 4 are the same as those shown in FIG. 2 and extend about three sides of the dome sets 40 and 41. The adjacent gutters 50 and 51 and retainer 44 provide for condensation collection intermediate the dome sets and a common retainer for the two dome sets at the junction therebetween. The unit described in FIGS. 3 and 4 functions in essentially the same fashion as that described in FIGS. 1 and 2.

What is claimed is:

1. A drop-out fire vent for a building comprising;

a pair of heat softenable plastic domes arranged one above the other,

means supporting the lower dome at its periphery over a skylight opening in the building and defined by vertical extending enclosing well walls,

said lower dome having a periphery extending outwardly of the inner periphery of said supporting means,

said upper dome being smaller than said lower dome and having its periphery terminating inwardly of the inner periphery of said supporting means to thereby expose a peripheral area of the lower dome that is not covered by the upper dome and that extends between the spaced peripheries of the domes,

and retainer means secured to said supporting means and including a flange extending to the periphery of the upper dome holding said upper dome in vertically spaced stationary relation over the periphery of the lower dome and in contact with the upper dome, said flange providing an enclosure covering the exposed peripheral area of the lower dome and extending between said periphery of said upper dome and said periphery of said lower dome.

2. The vent of claim 1 wherein said upper dome has a thickness greater than said lower dome.

3. The vent of claim 1 wherein said lower dome has a thickness on the order of 0.09 inches.

4. The vent of claim 1 wherein said lower dome is formed of an acrylic plastic which softens at temperatures in the order of 320 F.

5. The vent of claim 1 wherein said upper dome is smaller than the inner periphery formed by said enclosing well walls so as to permit said upper dome to pass into said well upon collapse of said lower dome.

6. The vent of claim 5 wherein said retainer means includes means for holding the outer periphery of said upper dome, said holding means contained in said enclosure.

7. The vent of claim 5 including sealing means disposed intermediate the outer periphery of said upper dome and said securing means.

8. The vent of claim 7 wherein said sealing means includes a gasket.

9. The vent of claim 5 wherein said retainer means further includes a second flange integral with the first flange, said flanges together coupling between the outer periphery of said upper dome and said well, and means for holding the outer periphery of said upper dome to limit its passing through said well.

10. The vent of claim 9 wherein said upper dome is sufficiently smaller than said lower dome to leave a relatively substantial peripheral area of the lower dome which is covered by the flanges.

l l. The vent of claim 10 wherein said flanges form an L-shaped member and further including a gasket fitting between one end of the L-shaped member and a flange defining the outer periphery of said upper dome.

12. The vent of claim 1 wherein the outer periphery of said lower dome is disposed just outward of the inner periphery of said well walls.

13. A drop-out fire vent for a building comprising;

a pair of heat softenable plastic domes arranged one above the other,

means supporting said other dome at its periphery over a skylight opening in the building defined by vertical extending enclosing well walls,

said other dome having a periphery extending outwardly of the inner periphery of said supporting means,

said one dome being smaller than said other dome and having its periphery terminating inwardly of the inner periphery of said supporting means,

and means securing said one dome over said other dome and providing an enclosure between said periphery of said one dome and said periphery of said other dome,

' said one dome being smaller than the inner periphery formed by said enclosing well walls so as to permit said one dome to pass into said well upon collapse of said other dome,

said securing means including means for holding the outer periphery of said one dome, said holding means being contained in said closure,

wherein said holding means includes a strap secured at one end to a flange defining the outer periphery of said one dome.

14. The vent of claim 13 wherein said enclosure is defined at least in part by a two sided member having a lower end supported by the well walls.

15. The vent of claim 14 wherein the other end of said strap is secured to the lower end of said two sided member. 

1. A drop-out fire vent for a building comprising; a pair of heat softenable plastic domes arranged one above the other, means supporting the lower dome at its periphery over a skylight opening in the building and defined by vertical extending enclosing well walls, said lower dome having a periphery extending outwardly of the inner periphery of said supporting means, said upper dome being smaller than said lower dome and having its periphery terminating inwardly of the inner periphery of said supporting means to thereby expose a peripheral area of the lower dome that is not covered by the upper dome and that extends between the spaced peripheries of the domes, and retainer means secured to said supporting means and including a flange extending to the periphery of the upper dome holding said upper dome in vertically spaced stationary relation over the periphery of the lower dome and in contact with the upper dome, said flange providing an enclosure covering the exposed peripheral area of the lower dome and extending between said periphery of said upper dome and said periphery of said lower dome.
 2. The vent of claim 1 wherein said upper dome has a thickness greater than said lower dome.
 3. The vent of claim 1 wherein said lower dome has a thickness on the order of 0.09 inches.
 4. The vent of claim 1 wherein sAid lower dome is formed of an acrylic plastic which softens at temperatures in the order of 320* F.
 5. The vent of claim 1 wherein said upper dome is smaller than the inner periphery formed by said enclosing well walls so as to permit said upper dome to pass into said well upon collapse of said lower dome.
 6. The vent of claim 5 wherein said retainer means includes means for holding the outer periphery of said upper dome, said holding means contained in said enclosure.
 7. The vent of claim 5 including sealing means disposed intermediate the outer periphery of said upper dome and said securing means.
 8. The vent of claim 7 wherein said sealing means includes a gasket.
 9. The vent of claim 5 wherein said retainer means further includes a second flange integral with the first flange, said flanges together coupling between the outer periphery of said upper dome and said well, and means for holding the outer periphery of said upper dome to limit its passing through said well.
 10. The vent of claim 9 wherein said upper dome is sufficiently smaller than said lower dome to leave a relatively substantial peripheral area of the lower dome which is covered by the flanges.
 11. The vent of claim 10 wherein said flanges form an L-shaped member and further including a gasket fitting between one end of the L-shaped member and a flange defining the outer periphery of said upper dome.
 12. The vent of claim 1 wherein the outer periphery of said lower dome is disposed just outward of the inner periphery of said well walls.
 13. A drop-out fire vent for a building comprising; a pair of heat softenable plastic domes arranged one above the other, means supporting said other dome at its periphery over a skylight opening in the building defined by vertical extending enclosing well walls, said other dome having a periphery extending outwardly of the inner periphery of said supporting means, said one dome being smaller than said other dome and having its periphery terminating inwardly of the inner periphery of said supporting means, and means securing said one dome over said other dome and providing an enclosure between said periphery of said one dome and said periphery of said other dome, said one dome being smaller than the inner periphery formed by said enclosing well walls so as to permit said one dome to pass into said well upon collapse of said other dome, said securing means including means for holding the outer periphery of said one dome, said holding means being contained in said closure, wherein said holding means includes a strap secured at one end to a flange defining the outer periphery of said one dome.
 14. The vent of claim 13 wherein said enclosure is defined at least in part by a two sided member having a lower end supported by the well walls.
 15. The vent of claim 14 wherein the other end of said strap is secured to the lower end of said two sided member. 